The GitHub Actions job "CI" on tvm-ffi.git/cold-code-layout has failed. Run started by GitHub user tqchen (triggered by tqchen).
Head commit for run: a9e26b6444bfe4054ec2a0825d427fad57bc1847 / tqchen <[email protected]> [BUILD] TVM_FFI_COLD_CODE macro and -ffunction-sections for cold code layout A binary-layout audit of libtvm_ffi.so showed that error-throw helpers (ErrorBuilder ctors/dtor, the TVMFFIError* C ABI exports) live in the middle of .text, interleaved with hot C ABI dispatch and container code. The entire library compiles into a single monolithic .text section because -ffunction-sections is not enabled, so the linker has no way to isolate cold code into a separate region. This change introduces a portable TVM_FFI_COLD_CODE attribute and enables -ffunction-sections on the object-library targets so the toolchain can place error-only code in a separate cold region of .text. With this, ErrorBuilder ctor/dtor and the TVMFFIError* exports move into the cold cluster at the head of .text (offsets 0x86f2 .. 0xc7fd in the final layout), and the hot TVMFFIBacktrace body shifts from 0x32e00 in baseline to 0x47b80 in the final build. Stripped libtvm_ffi.so shrinks from 1,887,800 to 1,826,368 bytes (-61,432, -3.3%), driven by tighter linker packing once functions live in their own sections. The change has three pieces: - A TVM_FFI_COLD_CODE macro in base_details.h that expands to [[gnu::cold]] on GCC/Clang and a no-op on MSVC, plus TVM_FFI_UNLIKELY / TVM_FFI_LIKELY wrappers around __builtin_expect. The macro is applied to ErrorBuilder ctors and the [[noreturn]] destructor (error.h), to SafeCallContext setter methods and the TVMFFIError* C ABI helpers (error.cc). - A new tvm_ffi_enable_section_layout() helper in cmake/Utils/Library.cmake that turns on -ffunction-sections (GCC, Clang, AppleClang) or /Gy (MSVC) on tvm_ffi_objs and tvm_ffi_extra_objs. --gc-sections is intentionally not enabled because tvm-ffi uses static-init registration patterns that the linker cannot trace; that is left for a follow-up. - TVM_FFI_UNLIKELY applied to a small set of representative error-check branches (the TVM_FFI_CHECK_SAFE_CALL macro, the TVM_FFI_CHECK macro, and GlobalFunctionTable::Update's already-registered check) to demonstrate the pattern without blanket-annotating the codebase. Numbers, symbol maps, and the rationale for skipping --gc-sections are written up in docs/dev/binary_layout.md. Report URL: https://github.com/apache/tvm-ffi/actions/runs/25810132507 With regards, GitHub Actions via GitBox --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
